The firearm dealer has a record of each sale. He must keep these records for review by the ATF/ATFE on demand. From these records, the dealer can provide the manufacturer, along with the serial number of the firearm and the sale date and to whom it was sold. If it was a private sale between individuals, there may be a record or there may not.
The dealer is required to retain them for 20 years. If, at any point before the 20 years that dealer shuts down their business (or it is shut down), those records are turned into (or confiscated by) the BATFE.
This depends on whether the dealer just folded or if the business was bought out by someone. A dealer going out of business is required to surrender his records to the ATF. If he is bought out, the buyer can keep the records, or he can choose to surrender them to the ATF anyway. You may try to contact ATF about those records.
The MB dealer should be able to access data pertinent to the VIN.
DROS is Dealer's Record of Sale. That is identifying information on you and the firearm.
No
Retention of the firearm, and access to it.
If you are a convicted felon, that is on your record and that information can be accessed by anyone who has access to NCIC, no matter what state you are in.
Yes
A reputable gun dealer should have access to those Walther records that detailed the date of manufacture.
sorry- no public serial number records.
Yes, but may not have access to the firearm (stored under lock and key that the felon has no access to)